I used to practice Eskrima in the weekends during my college days and in the style I practiced it placed great emphasis on eye movement to look at things because turning your head only created a blindspot. In addition, you'd be staring at "everything" in front of you, meaning you'd only see an attack with your periphery. So in practice, I'd be looking at my partner like a psycho with eyes wide barely blinking while sticks are flying around very fast. Years later, I stopped practicing Eskrima but the habits of eye movement are pretty much ingrained in my day-to-day. When I needed to replace my scratched-up glasses lens, I found that the lens grade I was comfortable wearing had lowered.